Peters



(No Model.) 4 Sheets-Sheet 1.

' J. MAG-TEAR.

FURNACE FOR OHBMIGALPR'OGESSES. 'No. 253,734. Patented Feb. 14,1882;

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FURNAUE FOR. GHEMIGAL PROCESSES.-

Patented Feb. 14,1882.

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(No Model.) v 4 Sheets-Sheet 3.

J. MAGTEAR. FURNACE FOB. GHEMfGAL PROCESSES.

No. 253,734. Patented Feb. 14,1882.

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N. PETERS. Phowukha n hn, Washingficn. D. C.

(No Model.) 4 Sheets-Sheet 4.

J. MAGTEAR. FURNACE FOB. CHEMICAL PROCESSES.

No. 253,734. Patented Feb. 14,1882.

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N. PETERS nmwmn ngrapher. Washington, D. c.

UNITE STATES P-ATENT OFFICE.

JAMES MAOTEAR, OF GLASGOW, COUNTY OF LANARK, SCOTLAND.

FURNACE FOR CHEMICAL PROCESSES.

SPECIFICATION forming part of Letters Patent No. 253,734, dated February14, 1882.

Application filed December 27, 1881. (No model.) Patented in EnglandNovember 28, 1879, in France December 16, 1880, and in Belgium May 23,1881.

furnaces employed for chemical processes by securing a practicallycontinuous action both in the feeding and in the discharging of thematerials.

My improvements are applied to a furnace having a horizontal circularrevolving bottom made of iron, combined with fire-brick or othersuitable refractory material, and formed with a raised rim around theouter edge. This furnace-bottom, which is mounted-on wheels and made torotate by means of suitable gearing, is covered by a brick-work roof,and is heated by one or more fires, the flames or firegases beingadmitted at one'side into the space between the furnace bottom and roof,and passing off by two outlets at the opposite side. At the part betweenthe outlets a set of stirrers are placed, consisting of blades or prongsfixed on the lower ends of vertical shafts driven by gearing at theirupper ends. The furnacebottom is formed with a central compartmentconsisting of a circular dish having a raised periphery'or rim, and fromthis central dish to the outer rim of the furnace-bottom there extends aflat, or nearly flat, fire-brick or other suitable surface.

The materials to be furnaced or heated are introduced into the centralcompartment or dish by preference continuously and at a regular rate.When the materials ar'e, for example, chloride of sodium and sulphuricacid for making sulphate of soda, the chloride of sodium may be fed inby means of a screw and the sulphuric acid be led by a pipe. As thematerials accumulate in the central dish they overflow over its edge orrim and spread 'over' the furnace-bottom, from the outer part of whichthe finished materials pass down'by one or more chiites ordischarge-ducts into a stationary channel placed beneath the rotatingfurnace-bottom.

The figures on the four accompanying sheets of drawings represent myimproved furnace as arranged for continuously decomposing salt orconverting sodium chloride into sulphate of soda, Figure 1 being anelevation; Fig. 2, a plan with the furnace-roof removed; Fig. 3, avertical section, and Figs. 4. to 9 enlarged views of details.

w The furnace bed or hearth 21, which is of a generally flat form andcircular in plan, is constructed with an iron frame-work, which ismounted on wheels 22, and is driven by means of a ring of spur-teeth,23, with which there gears a pinion, 24, on a vertical shaft, 25. Thisshaft 25, which serves also to drive the stirrers, as hereinafterexplained, receives its motion through bevel -wheels 26 from ahorizontal first-motion shaft, 27.

At the center of the hearth 21 there is a dish, 28, having a raised rim,into which dish the materials to be operated on are first supplied. Thisdish 28 may be constructed of the fire-brick or other suitablerefractory material of which the generalsurface of the hearth is formed;or it may be made of cast-iron with or without a refractory lining.

A raised rim or wall, 29, extends round the circumference of the hearth,and the hearth is covered by a brick-work root, 30, carried by anannular iron frame which rests on pillars, the space between the hearthand roof forming a reverberatory chamber which is heated by means of afurnaceor pair of furnaces (indicated by dotted lines at 31, Fig. 1)communicating with the chamber by a single flue, 32. From the inlet-flue32 the flames or fire-gases pass over the hearth 21 to the opposite sideand leave the chamber by two outlets, 33, a little on each side of apoint diametrically opposite to the inlet-flue 32. 'At the part betweenthe two outlets 33 there is aframing, 34, carrying vertical shafts 35,which have fixed to their lower ends forks or prongs 36 for stirring thematerials on the hearth 21. The stirrer-shafts 35 are geared together byspur-wheels 37, and are driven by a spur-wheel, 38, on the verticalshaft 25.

in a casing, 39, inserted in the roof of the furnace-chamber, the partsbeing shown enlarged in Fig. 7; and it can be raised or lowered, havingfixed or formed on it racks 40, with which there gear pinions 41 on ahorizontal shaft, 42. This pinion-shaft 42 has a worm-wheel, 43, on itsouter end, with which there gears a'worm on a shaft, 44, having asquared outer end to receive a crank-handle.

The stirrers 36 can be raised through separate openings in the casing 39for examination, repair, or renewal, and covers 45 are provided to closethe openings, these covers being made with rims which dip into sand orother suit-able luting material, and with boxes for luting or packingmaterial at the holes through which the stirrer-shafts 35 pass.

The driving spur-wheel 38is made with teeth of extra depth to allow ofsome vertical adjustment ofthe stirrer-shafts without the wheels gettingout of gear.

The furnace is delineated with feeding apparatus suitable for supplyingsodium chloride and sulphuric acid 5 but this apparatus may be modified,if necessary, for other materials. The sodium chloride is put into ahopper, 46, (shown in vertical section and enlarged in Fig. 4,) and fromthe bottom of this hopper a screwshaft, 47, conveys it along ahorizontal pipe or duct, 48, to a position directly above the centraldish or compartment, 28, of the hearth, audit falls thence into the dishthrough a d not or casing, 49. The sulphuric acid'is led continuously ata suitable rate through a pipe, 50, into the casing 49, or into anyconvenient part of a cover, 51, attached to the casing 49, and

covering an opening in the roof directly over the dish 28.

The screw feeding-shaft 47 is driven in a practically continuous mannerat a rate which can be varied or adjusted as is in practice found tobest suit the action of the furnace, and for this purpose it has fast onit a ratchet-wheel, 52, Figs. 5 and 6, which is acted on by apawl, 53,jointed to a lever, 54, and to this lever is connected one end of a rod,55, the other end of which is on a crank-pin on a shaft driven from thevertical shaft 25. The rod 55 is jointed on a block which can beadjusted inward or outward along the lever 54 by means of ascrewspindle, 56, and with this arrangement the re ciprocating motionimparted to the lever 54 can be made to turn the screw-shaft 47 to agreater or less extent at each stroke, as may be required.

In order to prevent the sodium chloride from hanging in the hopper 46,there is arranged inside a skeleton or frame, 57, consisting oflongitudinal ribs touching, or nearly touching, the sides of the coneand connected by rings. This frame 57 is attached to an upper toothedand flanged ring, 58, which rests by its flange upon the top edge or rimof the hopper, while its teeth are in gear with a pinion, 59, on avertical shaft, 60, driven by bevel-wheels 61 from the screw-shaft 47.By these means the skeleton or frame 57 is kept slowly turning, and itprevents the materials from adhering to the sides of the hopper andkeeps them in a loose condition, such as to insure their descent in auniform manner as the screw-shaft 47 gradually moves them away from thebottom of the hopper. The materials gradually overflow from the centraldish, 28, (being prevented from adhering to the sides of the dish by astationary scraper, 62,) and they gradually move outwardover the surfaceof the hearth 21, being thoroughly and repeatedly stirred by thestirrers 36, under which they are brought over and over again by therotation of the hearth 21.

The stirrers 36 are represented as not being wide enough to cover theentire space between them, in consequence of which there is a tendencyto the formation of low annular walls by the materials themselves, andthese quasi walls prevent the materials from working too rapidly outwardtoward the circumference of the hearth. This retarding action may bemade difierent in different cases by making the stirrers 36relativelywider or narrower, so as to more or less completely cover oroperate upon the space between the central dish, 28, and thecircumferenee.

A number of descending discharge-ducts, 63, are formed at thecircumference of the hearth 21, close to the rim or wall 29, and beneaththese there is a stationaryannular channel,64, to receive the materialsas they fall through the ducts or openings 63. The ducts 63 communicatewith or have attached to them an annular piece, 65, shaped like aninverted channel, and which forms a cover to the stationary channel 64,its sides dipping down into lute-grooves 66, formed upon the sides ofthe stationary channel 64. Portions of the ma terials enter thelute-grooves 66; or sand or other suitable lutin g materials may. be puttherein, so as to prevent the entrance of air into the furnace or theegress of gases or vapors therefrom.

The stationary channel 64 has fixed in connection with it one or morehopper-shaped discharge-boxes, 67, Fig. 1, fitted with bottom doors orvalves for periodically emptying the sulphate or other materials intotrucks or other receptacles.

The outer rim, 29, of the hearth 21 is beneath an annular plate orframe, 68, which is made up of separate pieces bound by a wrought-ironhoop, and is supported on pillars 69, and which supports, or partlysupports, the roof 30, and this plate 68 is formed with acylindricalflange, which has fixed to it a sheet-iron band, 70, dipping down intoan annular channel, 71, fixed to the revolving hearth, and having placedin held in guides against the vertical face of a bracket, 78, andpassing down through a box or casing providedwith a cover, 79. Theserods 77 can move independently of each other, their upper parts beingformed with slots, into which project pins fixed into the bracket 78 toprevent the rods from descending too far,while allowing them to riseover small obstructions, which action is also facilitated by theirbottom ends being beveled. The scrapers 77 serve to dislodge materialsfrom the parts of the hearth 21 between the discharge-openings 63.

My improved furnaces maybe fired by means of any suitable fuel; but Iprefer to employ coke, or to fire them by means of combustiblefurnace-gas, such as is formed in what are known as gas-producers.

What I clainras my invention in furnaces for chemicalprocesses isl. Incombination, a rotating hearth in a reverberatory chamber, the saidrotating hearth being made witha dish or rim med compartment at thecenter and with a raised rim at the circumference, continuous feedingapparatus for supplying materials to the central dish, and

continuous discharge apparatus/near the circumferential rim,substantially as and for the purposes set forth.

2. In combination, the feeding-screw 47, the ratchet 52, and pawl-lever54, with screw-adjustment to vary the stroke given by the connecting-rod55, the hopper 46, with its rotating skeleton-frame 57 58, the pipe 48,with its delivery-outlet above the central dish, 28, ot'therotatinghearth,and the saidrotatinghearth, all arranged and operatingsubstantially asset forth.

3. The continuous discharge apparatus consistin g of the ducts 63,fitted to the outer part of the rotating hearth,and having the annularchannel-cover 65 fixed to them, and also of the fixed annular channel 64and its discharge box or boxes 67, substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES MAGTEAR.

Witnesses:

EDMUND HUNT, ROBERT WYLIE.

